US5028735A - Purification and preparation processes for methyl methacrylate - Google Patents

Purification and preparation processes for methyl methacrylate Download PDF

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Publication number
US5028735A
US5028735A US07/501,716 US50171690A US5028735A US 5028735 A US5028735 A US 5028735A US 50171690 A US50171690 A US 50171690A US 5028735 A US5028735 A US 5028735A
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US
United States
Prior art keywords
methanol
water
hexane
mma
point fraction
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Expired - Lifetime
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US07/501,716
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English (en)
Inventor
Hirozo Segawa
Norio Ishikawa
Katsuji Yoguchi
Morimasa Kuragano
Minoru Koshibe
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Mitsui Chemicals Inc
Kuraray Co Ltd
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Kuraray Co Ltd
Mitsui Toatsu Chemicals Inc
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Assigned to MITSUI TOATSU CHEMICALS, INCORPORATED, KURARAY CO., LTD. reassignment MITSUI TOATSU CHEMICALS, INCORPORATED ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: ISHIKAWA, NORIO, KOSHIBE, MINORU, KURAGANO, MORIMASA, SEGAWA, HIROZO, YOGUCHI, KATSUJI
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Assigned to MITSUI CHEMICALS, INC. reassignment MITSUI CHEMICALS, INC. MERGER (SEE DOCUMENT FOR DETAILS). Assignors: MITSUI TOATSU CHEMICALS, INC.
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    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C29/00—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring
    • C07C29/74—Separation; Purification; Use of additives, e.g. for stabilisation
    • C07C29/88—Separation; Purification; Use of additives, e.g. for stabilisation by treatment giving rise to a chemical modification of at least one compound
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C57/00—Unsaturated compounds having carboxyl groups bound to acyclic carbon atoms
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C67/00—Preparation of carboxylic acid esters
    • C07C67/48—Separation; Purification; Stabilisation; Use of additives
    • C07C67/52—Separation; Purification; Stabilisation; Use of additives by change in the physical state, e.g. crystallisation
    • C07C67/54—Separation; Purification; Stabilisation; Use of additives by change in the physical state, e.g. crystallisation by distillation
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C69/00—Esters of carboxylic acids; Esters of carbonic or haloformic acids
    • C07C69/52—Esters of acyclic unsaturated carboxylic acids having the esterified carboxyl group bound to an acyclic carbon atom
    • C07C69/533—Monocarboxylic acid esters having only one carbon-to-carbon double bond
    • C07C69/54—Acrylic acid esters; Methacrylic acid esters
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S203/00—Distillation: processes, separatory
    • Y10S203/22—Accessories

Definitions

  • the present invention relates to a purification process for methyl methacrylate (hereinafter may be abbreviated as "MMA”) and also to a preparation process for MMA.
  • MMA methyl methacrylate
  • MMA is produced by esterifying methacrylic acid (hereinafter may be abbreviated as "MAA") or methacrylamide with methanol in the presence of sulfuric acid, a strongly acidic ion-exchange resin or the like.
  • MAA methacrylic acid
  • methanol methacrylamide
  • sulfuric acid a strongly acidic ion-exchange resin
  • Crude MMA which is obtained from this esterification process contains, in addition to water formed by the reaction and unreacted methanol and MAA, small amounts of lower boiling-point impurities, such as methyl acrylate (hereinafter may be abbreviated as "MA”) and methyl propionate (hereinafter may be abbreviated as "MP”), derived from impurities in the raw materials.
  • MA methyl acrylate
  • MP methyl propionate
  • An object of the present invention is to provide a process for the purification of MMA, which can almost completely remove low boiling-point impurities such as water, methanol, MA and MP without losing MMA, and also to furnish a process for preparing MMA by making use of the above purification process.
  • Another object of the present invention is to provide a process for the recovery of methanol as a raw material for the preparation of MMA, which enables the recovery of methanol in a form free of detrimental impurities such as MA and MP, and also to furnish processes for purifying and preparing MMA by using the above recovery process.
  • the present invention provides a purification process of MMA, which can be suitably applied for the preparation of MMA, namely, a process for the purification of methyl methacrylate, which comprises the following steps:
  • azeotropically distilling together with hexane, a mixture comprising water, methanol and MMA as principal components and containing at least one of MA, MP and MAA, thereby obtaining a high boiling-point fraction and a low boiling-point fraction, said high boiling-point fraction being substantially free of water, methanol, MA, MP and hexane and composed principally of MMA, said low boiling-point fraction being principally composed of water, methanol and hexane and containing at least one of MA and MP;
  • the present invention also provides a recovery process of methanol, which can be suitably applied for the purification and preparation of MMA, namely, a process for the recovery of methanol from a mixture comprising water and methanol as principal components and containing at least one of MA and MP, which comprises adding an alkaline substance to the mixture and then distilling the resultant mixture.
  • the present invention further provides a process for the preparation of MMA, which comprises esterifying with methanol at least one methacrylic compound selected from the group consisting of MAA and methacrylamide, thereby obtaining a mixture comprising water, methanol and MMA as principal components and containing at least one of MA, MP and MAA; and then subjecting the mixture to the above MMA purification process including the above recovery of methanol.
  • Hexane useful in the practice of the present invention forms a minimum boiling point azeotrope with water and methanol, which are both contained in crude MMA. Hexane therefore facilitates the removal of these impurities.
  • MMA itself acts as an entrainer and is hence azeotropically distilled together with water and methanol.
  • MMA which is polymerizable is recirculated inside a distillation column, so that troublesome polymerization tends to occur therein.
  • a condensate which is obtained by condensing a top distillate can hardly be separated into a water phase and an oil phase, because the difference in specific gravity between these phases is small.
  • impurities such as MA and MP in the condensate are distributed at only small rates into the water phase. As a result, only small portions of these impurities are discharged out of the system along with the water phase and impurities are therefore recirculated and accumulated in increasing quantities in the system.
  • top distillate in other words, overhead vapor is distilled out at a lower temperature and moreover, substantially no MMA is contained therein.
  • the troublesome polymerization can therefore be minimized.
  • the condensate of the top distillate can be easily separated into a water phase and an oil phase because there is a substantial difference in specific gravity between these phases. Further, the distribution of low boiling-point impurities,such as MA and MP into the water phase has been favorably improved, whereby the discharge of impurities to the outside of the system is facilitated.
  • the water phase which is discharged out of the system of the distillation column contains methanol useful as a raw material for the esterification. It is however impossible to recover methanol alone by distillation, because methanol and MA or MP mutually form a minimum boiling point azeotrope.
  • the present invention is also concerned with the effective process for the recovery of methanol from the water phase.
  • the water phase is first treated with an alkaline substance, followed by distillation. This has made it possible to recover, as a raw material for the preparation of MMA, methanol in a form free of detrimental impurities. It is also feasible to avoid the accumulation and recirculation of MA and MP in the process.
  • FIG. 1 is a flow diagram of a purification plant employed in an example of the present invention.
  • the term "crude MMA” means crude MMA obtained by esterifying MAA and/or methacrylamide with methanol The esterification is conducted at 60°-130° C. It is desired from the standpoints of process simplification and energy consumption to provide crude MMA for the purification process of the present invention after partly or substantially removing water, methanol and MAA therefrom by a conventional process.
  • Crude MAA subjected to the purification process of the present invention may preferably be a mixture containing 2-10% (by weight; all designations of "%” will hereinafter mean wt. %) of water, 2-15% of methanol, not more than 2% of MAA, not more than of 1% of MA or MP, and 75-95% of MMA.
  • Crude MMA is distilled in the presence of hexane by a distillation means led by a distillation column. Upon conducting this distillation, it is necessary to use hexane in an amount sufficient to distill out water, methanol and the like, which are contained in the crude MMA, by the azeotropic distillation. In practice, it is only necessary to replenish hexane to the distillation column by recycling an oil phase, which is separated from a low boiling-point fraction, to the distillation column as will be described herein.
  • the amount of hexane to be replenished to the distillation column preferably ranges from the sum of a 17-fold amount by weight of water and a 3-fold amount of methanol to the sum of a 50-fold amount by weight of water and a 10-fold amount of methanol. If hexane is replenished in an amount smaller than the lower limit, MMA is also distilled in the top distillate. It is hence not preferable to replenish hexane in such a small amount. No additional merit is brought about from the use of hexane in an amount greater than the upper limit, although no problem or inconvenience arises.
  • distillation it is preferable to conduct the distillation under normal or reduced pressure. To prevent polymerization of MMA, it is desired to lower the operation pressure. However, an unduly low operation pressure results in such problems that large facilities are needed and a low-temperature cooling medium has to be used because of a reduction in the condensation temperature of the low boiling-point fraction. It is therefore preferable to conduct the distillation in a pressure range of 300-760 mm Hg. Under such pressures, the top temperature ranges from 37° C. to 63° C.
  • a bottom substantially free of water, methanol, MA and MP is obtained as a high boiling-point fraction from the bottom of the distillation column.
  • this high boiling-point fraction still contains MAA and high boiling-point impurities in small amounts
  • high-purity MMA can be obtained by subjecting it to distillation again because impurities having boiling points close to MMA and water capable of forming an azeotropic mixture with MAA around the boiling point of MMA have already been removed.
  • the low boiling-point fraction composed principally of hexane is cooled and condensed, preferably at 5°-35° C. and then separated into a water phase and an oil phase in a reflux drum. Difficulties may be encountered upon separation of the condensate when the water content of the crude MMA employed as the raw material is low. Even in such a case, a water phase can still be formed by adding water to the reflux drum. A majority of hexane is distributed to the oil phase, whereas majorities of water and methanol are distributed to the water phase. Impurities such as MA and MP are distributed to both phases in accordance with their respective distribution coefficients.
  • the addition of water is effective not only in facilitating the separation of the condensate into two phases but also in reducing the concentrations of methanol, MA and MP in the oil phase.
  • the low boiling-point impurities separated from crude MMA such as MA and MP, can be removed along with water.
  • Methanol is recovered by treating t:his water phase with an alkaline substance and then distilling the resultant mixture.
  • an alkaline substance sodium hydroxide or potassium hydroxide can be used preferably.
  • the alkaline substance is added in an amount required to hydrolyze the above carboxylate esters contained in the water phase, namely, MA, MP and the like into their corresponding carboxylate salts.
  • the alkaline substance is used in a molar amount 1-2 times the sum of these carboxylate esters.
  • the alkaline substance can be added at any stage before the water phase separated in the reflux drum is subjected to distillation for the recovery of methanol. The hydrolysis reactions are completed while the water phase remains within the distillation column.
  • Crude MMA containing water, methanol, MA, MP and MAA was fed through a feed line 10 to a middle stage of a first distillation column 1 (inner diameter: 150 mm; height: 10 m; packings: 1/4" Berl saddles). Heat was supplied at the base of column 1 through heat exchanger or reboiler 2.
  • the crude MMA was distilled under the conditions that the operation pressure, top temperature and bottom temperature were controlled at 500 mm Hg, 54° C. and 90° C., respectively and the oil phase distilled was recycled in toto.
  • An oil phase composed primarily of hexane was recycled to an upper stage of the first distillation column 1, while a water phase composed principally of water was discharged to a next hydrolysis tank 5 by way of a line 15.
  • MMA Obtained from the bottom of the first distillation column 1 through line 11 was MMA, which was free of water and low boiling-point components but contained MAA and high boiling-point components in small amounts. High-purity MMA was successfully furnished by subjecting the thus-obtained MMA to rectification (not shown).
  • a 20% aqueous solution of sodium hydroxide was supplied to the hydrolysis tank 5 through a line 16, so that the water phase was maintained there at pH 13-13 5 and room temperature for 30 minutes.
  • the thus-hydrolyzed water phase was supplied through a line 17 to a middle stage of a second distillation column 6 (inner diameter: 80 mm; height: 5 m; packings: 1/4" Berl saddles).
  • Heat was supplied at the base of column 6 through heat exchanger or reboiler 7.
  • the water phase was distilled under normal pressure at a top temperature of 64° C., a bottom temperature of 100° C. and a reflux ratio of 4, whereby a methanol fraction 21 substantially free of MA and MP was recovered through line 19 and was condensed in condenser 8.
  • the condensate from condenser 8 was stored in tank 9 and was divided into a reflux and a distillate.
  • the reflux was returned to column 6 through line 21.
  • the aqueous bottom fractions, which were essentially methanol-free could be withdrawn from the base of column 6 through line 18.
  • Table 1 the liquid quantities delivered through principal lines are shown for respective components.

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  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
US07/501,716 1989-03-31 1990-03-30 Purification and preparation processes for methyl methacrylate Expired - Lifetime US5028735A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP1-78174 1989-03-31
JP7817489 1989-03-31

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US (1) US5028735A (de)
EP (1) EP0390577B1 (de)
KR (1) KR920003557B1 (de)
CN (1) CN1023799C (de)
CA (1) CA2012935A1 (de)
DE (1) DE69010046T2 (de)

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5187309A (en) * 1989-08-03 1993-02-16 Elf Atochem S.A. Process for the continuous preparation of lower acrylates
US5236559A (en) * 1993-01-22 1993-08-17 Lloyd Berg Separation of hexane from vinyl acetate and methyl acrylate by extractive distillation
US5435892A (en) * 1993-08-30 1995-07-25 Mitsubishi Rayon Co., Ltd. Process for separating methanol and methyl acrylate or methyl methacrylate
US5990343A (en) * 1997-02-07 1999-11-23 Rohm And Haas Company Process for producing butyl acrylate
US6494996B2 (en) * 2001-01-22 2002-12-17 Celanese International Corporation Process for removing water from aqueous methanol
US20100056742A1 (en) * 2006-12-08 2010-03-04 Evonik Roehm Gmbh Process and apparatus for preparing alkyl esters of methacrylic acid
WO2016069227A1 (en) 2014-10-31 2016-05-06 Dow Global Technologies Llc Separation process
WO2016069198A1 (en) 2014-10-31 2016-05-06 Dow Global Technologies Llc Breaking a methanol/methyl methacrylate azeotrope using pressure swing distillation
CN105636929A (zh) * 2013-10-18 2016-06-01 阿肯马法国公司 用于纯化粗甲基丙烯酸甲酯的单元和方法
US9487469B2 (en) 2013-08-09 2016-11-08 Gas Technology Institute Process for purification of methyl methacrylate using molecular sieve membranes
RU2612254C1 (ru) * 2016-04-22 2017-03-03 Общество с ограниченной ответственностью "ТрансЛитХ" Способ утилизации кубовых остатков производства метилметакрилата
US20180346403A1 (en) * 2015-12-18 2018-12-06 Rohm And Haas Company Process for purification of methyl methacrylate
US10597349B2 (en) 2015-12-18 2020-03-24 Dow Global Technologies Llc Process for purification of methyl methacrylate
CN115850073A (zh) * 2022-11-28 2023-03-28 中国海洋石油集团有限公司 一种制备甲基丙烯酸甲酯的方法及装置

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE69511238T2 (de) * 1995-04-07 1999-12-16 Mitsubishi Rayon Co Verfahren zum Trennen von Methanol und Methylacrylat oder Methylmethacrylat
JP2005247714A (ja) * 2004-03-02 2005-09-15 Mitsubishi Chemicals Corp （メタ）アクリル酸の製造方法
CN101234970B (zh) * 2008-02-18 2010-04-07 济南大学 柱层析法提纯甲基丙烯酸多苯乙烯烷基酚乙氧基酯的方法
CN102372631B (zh) * 2010-08-17 2014-05-07 上海伟佳家具有限公司 一种回收甲基丙烯酸甲酯的方法
CN101967099B (zh) * 2010-11-05 2013-04-17 辽宁科隆精细化工股份有限公司 一种二甲基二碳酸酯的提纯方法
KR101346685B1 (ko) * 2012-03-23 2014-01-03 이범식 액체 증발농축 시스템
CN106938971A (zh) * 2016-12-20 2017-07-11 江苏常州酞青新材料科技有限公司 一种丙烯酸甲酯（ma）与丙酸甲酯（mp）的分离方法
CN113457186B (zh) * 2020-03-30 2022-10-04 中石油吉林化工工程有限公司 提高粗mma分离塔分离效果的方法

Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2406561A (en) * 1943-12-27 1946-08-27 Nasa Azeotropic distillation of methanol from admixture with acrylic esters
US2614072A (en) * 1947-12-19 1952-10-14 Standard Oil Dev Co Separation of mixtures containing alcohols, aldehydes, and ketones
GB935543A (en) * 1959-03-05 1963-08-28 Celanese Corp Purification of acrylic acid esters
US3960672A (en) * 1971-02-09 1976-06-01 Veba-Chemie Ag Continuous distillation process for purifying alkanols
JPS51108004A (en) * 1975-03-14 1976-09-25 Mitsubishi Gas Chemical Co Metanooruno seiseihoho
US3990952A (en) * 1974-10-10 1976-11-09 Raphael Katzen Associates International, Inc. Alcohol distillation process
JPS58203940A (ja) * 1982-05-25 1983-11-28 Toagosei Chem Ind Co Ltd メタクリル酸メチルの回収方法
US4518462A (en) * 1980-06-20 1985-05-21 Asahi Kasei Kogyo Kabushiki Kaisha Distillation process for purifying methyl methacrylate
JPS62123150A (ja) * 1985-11-25 1987-06-04 Mitsui Toatsu Chem Inc メタクリル酸メチルの精製法
US4791221A (en) * 1985-07-11 1988-12-13 Francaise D'organo Synthese Transesterification of methyl methacrylate

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS51146418A (en) * 1975-06-10 1976-12-16 Nippon Zeon Co Ltd Purification of methacrylic esters

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2406561A (en) * 1943-12-27 1946-08-27 Nasa Azeotropic distillation of methanol from admixture with acrylic esters
US2614072A (en) * 1947-12-19 1952-10-14 Standard Oil Dev Co Separation of mixtures containing alcohols, aldehydes, and ketones
GB935543A (en) * 1959-03-05 1963-08-28 Celanese Corp Purification of acrylic acid esters
US3960672A (en) * 1971-02-09 1976-06-01 Veba-Chemie Ag Continuous distillation process for purifying alkanols
US3990952A (en) * 1974-10-10 1976-11-09 Raphael Katzen Associates International, Inc. Alcohol distillation process
JPS51108004A (en) * 1975-03-14 1976-09-25 Mitsubishi Gas Chemical Co Metanooruno seiseihoho
US4518462A (en) * 1980-06-20 1985-05-21 Asahi Kasei Kogyo Kabushiki Kaisha Distillation process for purifying methyl methacrylate
JPS58203940A (ja) * 1982-05-25 1983-11-28 Toagosei Chem Ind Co Ltd メタクリル酸メチルの回収方法
US4791221A (en) * 1985-07-11 1988-12-13 Francaise D'organo Synthese Transesterification of methyl methacrylate
JPS62123150A (ja) * 1985-11-25 1987-06-04 Mitsui Toatsu Chem Inc メタクリル酸メチルの精製法

Cited By (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5187309A (en) * 1989-08-03 1993-02-16 Elf Atochem S.A. Process for the continuous preparation of lower acrylates
US5236559A (en) * 1993-01-22 1993-08-17 Lloyd Berg Separation of hexane from vinyl acetate and methyl acrylate by extractive distillation
US5435892A (en) * 1993-08-30 1995-07-25 Mitsubishi Rayon Co., Ltd. Process for separating methanol and methyl acrylate or methyl methacrylate
US5990343A (en) * 1997-02-07 1999-11-23 Rohm And Haas Company Process for producing butyl acrylate
US6180819B1 (en) 1997-02-07 2001-01-30 Rohm And Haas Company Process for producing butyl acrylate
US6494996B2 (en) * 2001-01-22 2002-12-17 Celanese International Corporation Process for removing water from aqueous methanol
US20100056742A1 (en) * 2006-12-08 2010-03-04 Evonik Roehm Gmbh Process and apparatus for preparing alkyl esters of methacrylic acid
US9637574B2 (en) * 2006-12-08 2017-05-02 Evonik Röhm Gmbh Process and apparatus for preparing alkyl esters of methacrylic acid
US9487469B2 (en) 2013-08-09 2016-11-08 Gas Technology Institute Process for purification of methyl methacrylate using molecular sieve membranes
CN105636929A (zh) * 2013-10-18 2016-06-01 阿肯马法国公司 用于纯化粗甲基丙烯酸甲酯的单元和方法
US10793505B2 (en) * 2013-10-18 2020-10-06 Arkema France Unit and process for purification of crude methyl methacrylate
WO2016069198A1 (en) 2014-10-31 2016-05-06 Dow Global Technologies Llc Breaking a methanol/methyl methacrylate azeotrope using pressure swing distillation
WO2016069227A1 (en) 2014-10-31 2016-05-06 Dow Global Technologies Llc Separation process
US10059651B2 (en) 2014-10-31 2018-08-28 Dow Global Technologies Llc Separation process
US10144698B2 (en) 2014-10-31 2018-12-04 Dow Global Technologies Llc Breaking a methanol/methyl methacrylate azeotrope using pressure swing distillation
US20180346403A1 (en) * 2015-12-18 2018-12-06 Rohm And Haas Company Process for purification of methyl methacrylate
US10487038B2 (en) * 2015-12-18 2019-11-26 Dow Global Technologies Llc Process for purification of methyl methacrylate
US10597349B2 (en) 2015-12-18 2020-03-24 Dow Global Technologies Llc Process for purification of methyl methacrylate
RU2612254C1 (ru) * 2016-04-22 2017-03-03 Общество с ограниченной ответственностью "ТрансЛитХ" Способ утилизации кубовых остатков производства метилметакрилата
CN115850073A (zh) * 2022-11-28 2023-03-28 中国海洋石油集团有限公司 一种制备甲基丙烯酸甲酯的方法及装置

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Publication number Publication date
CA2012935A1 (en) 1990-09-30
EP0390577B1 (de) 1994-06-22
EP0390577A2 (de) 1990-10-03
KR920003557B1 (ko) 1992-05-04
DE69010046D1 (de) 1994-07-28
CN1023799C (zh) 1994-02-16
KR900014294A (ko) 1990-10-23
DE69010046T2 (de) 1994-10-13
CN1046518A (zh) 1990-10-31
EP0390577A3 (de) 1991-02-27

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